package gold.digger;

import gold.utils.InputUtil;

/**
 * Created by fanzhenyu02 on 2020/6/27.
 * common problem solver template.
 */
public class LC547 {
    public long startExecuteTime = System.currentTimeMillis();


    class Solution {
        class UF {
            // 连通分量个数
            private int count;
            // 存储一棵树
            private int[] parent;
            // 记录树的“重量”
            private int[] size;

            public UF(int n) {
                this.count = n;
                parent = new int[n];
                size = new int[n];
                for (int i = 0; i < n; i++) {
                    parent[i] = i;
                    size[i] = 1;
                }
            }

            /* 将 p 和 q 连接 */
            public void union(int p, int q) {
                int rootP = find(p);
                int rootQ = find(q);
                if (rootP == rootQ)
                    return;

                // 小树接到大树下面，较平衡
                if (size[rootP] > size[rootQ]) {
                    parent[rootQ] = rootP;
                    size[rootP] += size[rootQ];
                } else {
                    parent[rootP] = rootQ;
                    size[rootQ] += size[rootP];
                }
                count--;
            }

            /* 判断 p 和 q 是否连通 */
            public boolean connected(int p, int q) {
                int rootP = find(p);
                int rootQ = find(q);
                return rootP == rootQ;
            }

            private int find(int x) {
                while (parent[x] != x) {
                    // 进行路径压缩
                    parent[x] = parent[parent[x]];
                    x = parent[x];
                }
                return x;
            }

            /* 返回图中有多少个连通分量 */
            public int count() {
                return count;
            }
        }


        public int findCircleNum(int[][] M) {
            UF uf = new UF(M.length);
            for (int i = 0; i < M.length; i++) {
                for (int j = i; j < M.length; j++) {
                    if (M[i][j] == 1) uf.union(i, j);
                }
            }

            return uf.count;
        }
    }

    public void run() {
        Solution solution = new Solution();
        int[][] arr = InputUtil.toDoubleIntegerArray("[[1,1,0],\n" +
                "[1,1,1],\n" +
                "[0,1,1]]");
        System.out.println(solution.findCircleNum(arr));
    }

    public static void main(String[] args) throws Exception {
        LC547 an = new LC547();
        an.run();

        System.out.println("\ncurrent solution total execute time: " + (System.currentTimeMillis() - an.startExecuteTime) + " ms.");
    }
}
